Fuze for projectiles



Sept.'23, 1947. l J. B. SEMPLE FUZE FOR PROJECTILES Filed July 20, 1943 INVENTOR JoJznB. Sample Patented Sept. 23, 1947 UNITED STATES PATENT OFFICE FUZE FOR PROJECTILES John B. Semple, Sewickley, Pa.

Application July 20, 1943, Serial No. 495,412

Claims.

This invention relates to fuzes for projectiles. Novelty lies in structure; and utility, in simplicity, safety, and certainty of performance.

A fuze embodying the invention is illustrated in the accompanying drawings. Fig. I is a View of thefuze in axial section; 'Fig. 11 is a view, also in axial section, on the plane at right angles to that of Fig. I--on the plane indicated by the line II-II, Fig. I. Fig. III is a view in transverse section, on theplane indicated at III-III, Fig. I. Fig. IV is afragmentary view in section, on the plane IV IV, Fig. I. Fig. V is a fragmentary view-in section, on the plane V--V, Fig. III.

The fuze is a percussion fuze, functioning on impact. The example given in the drawings is a point fuze; this, however, is a characteristic thatis not essential to the invention. The fuze is adapted to be arranged on the axis of the projectile that carries it. The body I of the fuze is essentially cylindrical in shape, with the qualification that, when designed as a point fuze, it shall taper forwardly, in the form of a parabolic conoid. Within-the body I is formed an axial cylindrical recess 2, open rearwardly but extendingforwardlypart away through the length of the fuzebody.

Within this cylindrical recess a permission plunger 3 is arranged. This is essentially a cylindrical body, conforming in shape and size to the recess, subject'to restraints presently to be described, but otherwise freely movable within therecess. Its range of-longitudinal movement is,'however, limited, and it is held captive within the recess by means of a rearward facing shoulder 31 formed exteriorly upon it, and a bushing -4 screwed to place in the mouth of the recess, torearward of the introducedplunger.

Of the fuze bodyl and the plunger 3, one carries a percussion cap and the other a firing-pin. In the functioning of the fuze the plunger drives forward within the recess, the cap and firing-pin come to forcible impact, and the cap is firedand this firing is the initial impulse in the normal functioning of the fuze and bursting of the shell. As here shown (Fig.'V) it is the fuze body I that carries the percussion cap 5 and it is the plunger 3 that carries the firing-pin B.

The plunger is axially perforate from end to end, and the'perforation' is enlarged rearwardly, toform a chamber for the booster charge C. It is a feature of invention that the booster charge is carried-by the percussion plunger. Provision is made for the transmission of the firing impulsefrom the percussion cap, through the perforation -in the plunger, to the plunger-borne booster charge.

Within the plunger 3, and forwardly of the enlarged chamber that carries the booster charge, is formed a transversely and diametrically extending essentially cylindrical bore 1.

The axis' of the bore intersects that of the plunger. The bore -is conveniently formed to extend entirely through the plunger, and its otherwise open ends are closed by a subsequently applied sleeve 8. Within this transverse bore is arranged a cylindrical block 9. The block fills the bore, but the proportions are minutely such and the opposed surfaces such in finish that the block when unrestrained can roll freely within the bore.

The block 9 is provided with a diametrically extending transverse bore [0 which in the range of the-rolling ofthe block within the bore advances from a remote position to a position of coincidence with the axial perforation through the plunger 3. This bore is filled with a charge I! of detonation-initiating material. When the block is held with its bore in remote position the fuze is safe; no premature firing of the sensitive elements in the lineof detonation transmission can reach the booster charge C tofire it; when, however, the block rolls and brings the bore with its charge to alignment with the axial bore through the plunger the fuze is armed and ready for firing.

Transversely throughthe plunger 3, and at a properly spaced interval from the bore 1, a second diametrical bore I2 is formed. This bore isangularly arranged relatively to bore 1; and it intersects bore 1, so that each bore throughout the extent of the intersection overlaps the other. This will be apparent on considering Figs. I and II. In the second bore, the bore [2, is arranged'a pair of identical spring-backed bolts I3 of substantial length and mass, that in the assembly meet on the-axis of the fuze, as clearly shown in Fig. II. The backing springs M are confined by the sleeve 8. The rolling block 9 is provided on its cylindrical face with a notch l5 of cylindrical curvature, which notch, when the block is in inactive'position is coincident with and forms part of the walls of the bolt-containing bore I'Z. Comparison of Figs. I and II will show that the bolts l3, l3 form a lock, securing the block- 9-in inactive, safety position.

Since the two bolts I3, [3 in the assembly meet end to end, and are both spring-backed, it is manifest that under all circumstances prior to firing they will jointly-be efiective as a look upon block 9. No jar can separate them. It is only when the projectile has'been fired from a rifled gun and isrotating at a high rate that centrifugal force acting upon them will cause them to recede oppositely and to release the block 9, so that it may roll.

The rolling block Sis additionally provided with a transverse bore or bores 9', here shown to be two in number, as is convenient, arranged symmetrically, toward' the ends of the block; and thesebores are so arranged that when the bore 3 that carries the detonation-transmitting charge II is in the remote and safe position (Fig. II) these bores 9 also will extend obliquely to the length of the fuze (Fig. IV). Indeed, the bores 9' are parallel with the bore that carries the charge II, and it may be understood that the obliquity of these bores when the block is locked in safe position is of the order of 60. The bores 9 by their presence produce a lack of symmetry in the disposition of the mass of the block with respect to its axis such that, when (the block being in the position indicated in Figs. II and IV and free to move) the fuze is rotated on its axis, the block will roll within its bore from the position of obliquity shown to a position in which the bore filled with the detonation-initiating charge II will be aligned with the axial perforation through the plunger 3.

Longitudinal bores I6 are formed in the fuze body I, and aligned longitudinal bores 3' are formed in the plunger at its anterior end, and in these bores posts II are set. The bores correspond in number and position with the bores 9 in the rolling block 9, so that, when the block 9 rolls from safe to armed position (with the charge I I in position of alignment with the axial bore through the percussion block) the bores 9 will be aligned with the bores that carry the posts II. The posts I1 are of such length that, when the block 9 is in safe position, they bear rearwardly upon the normal cylindrical surface of the block 9 and fill all the space between that surface and the bottoms of the bores I6 in the fuze body. Thus the posts are eifective to secure the percussion plunger 3 in its rearward position, as seen in Fig. I Extending as they do into the bores 3, the posts I I are at all times efi'ective to secure the plunger against turning. When, however, block 9 has rolled to armed position, and the bores e have come to alignment with the posts W, the posts are no longer a restraint, but the plunger is free to advance-the posts I1 passing into the bores 9' as the block 9, borne by the plunger 3, advances upon them. Thus it appears that the bores 9 in the rolling block 9 have two functions. The first is to afford such an inequality in the distribution of the mass of the block as to cause it, under the influence of centrifugal force, to roll in the containing bore; and the second is to afford passageway at proper time for the posts I! and so to allow the percussion plunger 3 to advance, telescoping upon the bolts. It will be found convenient to form the bores IS in the fuze body of such size that the posts I! will fit snugly within them, and to form the bores 3' and 9' of such size that the plunger 3 may advance readily upon the posts.

A spring I8 arranged between the body I of the 'fuze and the anterior face of the percussion plunger 3 tends to hold the plunger to rearward and the firing-pin remote from the primer.

Referring to Figs. III and V the firing-pin and primer will be seen, arranged in an axial plane of the fuze that is angularly disposed relatively to the planes of Figs. I and II.

The plunger, in this case, carries the firingpin 6, and the fuze body carries the primer 4. The primer is set in a longitudinal bore in the fuze body spaced somewhat from the axis, and the firing-pin is correspondingly placed in the plunger. (It will be borne in mind that, by virtue of the posts I I, the plunger is secure against rotational displacement within the fuze body.) The fuze as here illustrated may be understood to be a delay-action fuze; and, accordingly, within 4 the bore in the fuze body and beyond the primer 4, but in position to be ignited by the exploding primer, a delay pellet I9 is arranged. Beyond the delay pellet is a small body 20 of black powder, filling the anterior endof the bore, and through a trans'verse bore there is communication to an r axial bore 2| that opens rearwardly in alignment with the axial bore through the percussion plunger 3. In the transverse bore is set a relay explosive pellet 22.

The drawings show the fuze in its normal, inactive, and safe positionthe position maintained up to the time of firing from a gun. It is impossible for the rolling block 9 to turn, for it is locked by the bolts I3, I3. Spring-backed, they may be displaced under jar, but they move as a unit and maintain the locking effect. When the eiTect of such a displacing jar is spent, the springs will bring them again to the normal symmetrical position shown. The percussion plunger 3 is held from driving forward, and the firing-pin is held remote from the primer by the posts I! that bear rearwardly upon the block 9 within the plunger. Any premature firing of any sensitive portion of the fuze charge will be without effect. Itcannot reach the booster charge.

Operation is as follows. When a shell equipped with the fuze is fired from a gun it is set in rotation. Under centrifugal force the bolts I3, compressing springs I4, will recede and will release the block 9. The block 9 then, in response to centrifugal force, will roll within the containing bore until the mass is balanced-that is, until the bore I0 filled with charge I I comes to alignment with the axial perforation through the plunger 3. In such disposition of parts the fuze will continue during the flight of the shell. 'So long as acceleration in flight continues, the percussion plunger will be held by inertia in the rearward position, and, after acceleration is spent, the spring l8 will be effective to continue the plunger in the same rearward position. On impact, however, the plunger will drive forward, telescoping upon the posts II, the firing-pin will impinge upon and explode the primer; the delay pellet will be ignited, and it, burning away, will ignite the body I4 of black powder; the relay explosive pellet will then be fired, and the flash of its firing will spurt through the bore 2! and impinge upon the charge I I within the rolling block. That charge, now aligned in the axial bore, will be fired and will impart detonation to the booster charge 0, and the bursting of the shell will follow.

The range of the forward drive of the percussion plunger is, according to the drawings, about three sixteenths of an inch; but the firing of the primer is actually effected within a much narrower range of drive. The plunger will not advance to the limit of its range; but, even so, the actual range is so slight, relatively to the mass and cross-sectional size of the booster charge, that there will be no failure of the booster to detonate the burster charge of the shell. Never before, to my knowledge, has a booster charge so been mounted in a plunger. I have found it not a matter of indifference so to do in that the booster functions just as well as though it were stationary relatively to the burster chargebut I find it advantageous, for thus the mass of the booster charge itself is turned to advantage as an effective part of the mass of the plunger as a whole, and saving of material is realized.

I claim as my invention:

1. In a fuze for projectiles in which are found a fore-and-aft runway within the rum body and a percussion plunger movable in such runway, locking and guiding means for such plunger consisting of a cylindrical bore formed transversely within the plunger, a second bore formed longitudinally within the plunger and extending from the anterior end of the plunger to the bore first named, a cylindrical block arranged within and adapted to roll within the bore first named, the block penetrated by a bore transverse to its own longitudinal extent, the mass of the block being asymmetrically disposed with respect to its own cylindrical axis, whereby in response to the rotation of the shell-borne fuze the block "tends to rollwithin its bore from safe position to a position in which its transverse bore is in alignment with the bore above defined that extends longitudinally in the plunger, a post borne by the fuze body and extending rearwardly through the bore that extends longitudinally within the plunger, upon which post the said block when in safe position abuts, and movable means normally securing the rolling block in safe position.

2. The structure of claim 1, the means for normally securing the block in safe position consisting of a bore extending transversely through the plunger intersecting the cylindrical bore first named and extending in part through the rolling block within the bore, so that the wall of the last-named bore is formed in part and in the medial portion of its extent by a recess in the rolling block, such last-named bore crossing the axis of the fuze body, a pair of bolts arranged in such last-named bore and normally abutting end to end within the bore and in the axis of the fuze body, and springs backing the bolts severally and tending to hold them to such abutment.

3. In a fuze for projectiles in which are round a fore-and-aft runway within the 'fuze body and a percussion plunger movable in such runway, such plunger being penetrated by a longitudinally extending path of detonation transmission, the invention herein described of a cylindrical bore formed transversely within the plunger, a second bore formed longitudinally within the plunger and extending from the anterior end of the plunger to the bore first named, a chargebearing cylindrical block arranged within and adapted to roll within the bore first-named, from a safe position to an armed position in which the block-carried charge is aligned in such path of detonation transmission, the said rolling block being penetrated by a bore transverse to its own longitudinal extent, the mass of the block being asymmetrically disposed with respect to its own cylindrical axis, whereby in response to the rotation of the shell-borne fuze the block tends to roll within its bore from safe position to a position in which the block-borne charge is aligned in the path of detonation transmission and the tranverse bore through the block is aligned with the bore that extends longitudinally in the plunger, a .post borne by the fuze body and extending rearwardly through the bore that extends longitudinally within the plunger, upon which post the said block when in safe position 6 abuts, and movable means normally securing the rolling block in safe position.

4. A fuze for projectiles comprising a body, a plunger slidably received in the body and movable in a fore-and-aft direction, a rotatable member in the plunger extending crosswise thereof and having a passage extending diametrically therethrough, said passage containing a detonating charge, the rotatable member being adapted upon rotation of the fuze in flight to revolve about its axis to move said passage from an inoperative to an operative position, means in the body normally bearing against the rotatable member and rendered inoperative by rotation of the, rotatable member for normally liolding the plunger against sliding movement in the body, means movable to a release position upon rotation of the fuze in flight for normally locking said rotatable member against rotation, said means comprising a pair of transversely disposed normally abutting locking bolts oppositely movable under centrifugal action out of abutting and operative relation upon rotation of the fuze in flight, the rotatable body having a peripheral portion against which the locking bolts bear in their normal operative position 'for holding the member from rotation, and cooperating pin and cap elements on the plunger and body for firing the fuze wlhen relative longitudinal movement of the plunger and body occurs.

5. A fuze for projectiles comprising a body, a plunger slidably received in the body and movable in a fore-and-aft direction therein, a rotatable member in the plunger extending crosswise thereof and having a passage extending transversely therethrough, said passage containing a detonating charge, the rotatable member being adapted 'upon rotation of the fuze in flight to revolve about its axis to move the said passage from an inoperative to an operative position, a post on the body bearing against the periphery of the rotatable member for normally restraining the plunger against sliding movement in the body, said rotatable member having an opening into which the post may project when the rotatable member turns to a position where the passage containing the detonating charge is in an operative position to thereby permit the plunger to slide in the body, means movable to a release position upon rotation of the fuze in flight for normally locking said rotatable member against rotation, and cooperating pin and elements on the plunger and body lfOI firing the fuze when relative longitudinal movement of the plunger and body occurs.

JOHN B. SEMPLEL REFERENCES CITED The following references are of record in the 

